[pgpool-general: 4297] Re: Pgpool watchdog 3.4

[Yugo Nagata]

Hi Derek,

On Wed, 6 Jan 2016 18:50:36 +1100
Derek <derek_kouch at yahoo.com.au> wrote:

> Hi Yugo and Usama,
> 
> Could these trusted servers not be pgpool or Postgres servers? Eg, could the trusted server be the domain controller?

trusted servers could be any host which can repond to ping. It is intented to
use these to check the connection between pgpool and the client side network,
so GW or FW could be specified. Of course, the domain controller also could be.

> 
> Version 3.5 sounds like a good step up from the current version, can't wait to try out the stable release. Keep up the good work.
> 
> 
> 
> Kind regards,
> Derek.
> 
> > On 6 Jan 2016, at 3:46 PM, Yugo Nagata <nagata at sraoss.co.jp> wrote:
> > 
> > Hi Derek,
> > 
> > Although watchdog in pgpool-II 3.4 doesn't communicate after reconnecting
> > as Usama said, trusted_servers is one of the paramters to avoid split-brain.
> > 
> > If this is specified, watchdog tries to ping to these servers, and when this
> > fails, the local pgpool-II is regarded as down, so this can't become active
> > or standby until restarted.
> > 
> > http://www.pgpool.net/docs/latest/pgpool-en.html#TRUSTED_SERVERS
> > 
> > 
> > On Tue, 5 Jan 2016 17:24:27 +0500
> > Muhammad Usama <m.usama at gmail.com> wrote:
> > 
> >> Hi Derek
> >> 
> >> Unfortunately the watchdog in pgpool-II 3.4 and older version does not
> >> handle the network isolation and split-brain situations very well.
> >> Currently we are in the process of overhauling the watchdog for pgpool-II
> >> 3.5 which is in the beta at the moment and is planned to be released
> >> sometime this month. The new enhanced watchdog for pgpool-II 3.5 has
> >> addressed this and other watchdog related issues and hopefully will provide
> >> a better experience and more features.
> >> 
> >> Thanks
> >> Best regards
> >> Muhammad Usama
> >> 
> >>> On Tue, Jan 5, 2016 at 11:33 AM, Derek <derek_kouch at yahoo.com.au> wrote:
> >>> 
> >>> Hi,
> >>> 
> >>> I've got a split brain question. Sorry for the long email.
> >>> 
> >>> If the master pgpool server is disconnected from the network but is still
> >> running, when it reconnects after 10 minutes or longer, the master pgpool
> >> server's watchdog is still thinks it is still the master and it thinks the
> >> other pgpool server is down. However, it has lost the virtual ip to a new
> >> master. So when the new master is down, the old master does not get the
> >> virtual ip back because it still thinks it is already the master. In the
> >> end, the virtual ip is down.
> >>> 
> >>> Does the watchdog communicate with each other after reconnecting to the
> >> network after a long absence?
> >>> 
> >>> Is there a setting that I need to set to get the watchdogs to talk to
> >> each and to resolve who is the true master and who should get control of
> >> the virtual ip?
> >>> 
> >>> 
> >>> Kind regards,
> >>> Derek.
> >>> _______________________________________________
> >>> pgpool-general mailing list
> >>> pgpool-general at pgpool.net
> >>> http://www.pgpool.net/mailman/listinfo/pgpool-general
> > 
> > 
> > -- 
> > Yugo Nagata <nagata at sraoss.co.jp>


-- 
Yugo Nagata <nagata at sraoss.co.jp>